150 TOP STRENGTH of Materials Multiple Choice Questions and Answers

Strength of Materials Multiple choice Questions :-

1. Strain is defined as the ratio of
(a) change in volume to original volume
(b) change in length to original length
(c) change in cross-sectional area to original cross-sectional area
(d) any one of the above
(e) none of the above.Ans: d

8. A thin mild steel wire is loaded by adding loads in equal increments till it breaks. The extensions noted with increasing loads will behave as under
(a) uniform throughout
(b) increase uniformly
(c) first increase and then decrease
(d) increase uniformly first and then increase rapidly
(e) increase rapidly first and then uniformly.Ans: d

10. If the radius of wire stretched by a load is doubled, then its Young’s modulus will be
(a) doubled
(b) halved
(c) become four times
(d) become one-fourth
(e) remain unaffected.Ans: e

11. The ultimate tensile stress of mild steel compared to ultimate compressive stress is
(a) same
(b) more
(c) less
(d) more or less depending on other factors
(e) unpredictable.Ans: b

12. Tensile strength of a material is obtained by dividing the maximum load during the test by the
(a) area at the time of fracture
(b) original cross-sectional area
(c) average of (a) and (b)
(d) minimum area after fracture
(e) none of the above.Ans: b

13. The impact strength of a material is an index of its
(a) toughness
(b) tensile strength
(c) capability of being cold worked
(d) hardness
(e) fatigue strength.Ans: a

14. The Young’s modulus of a wire is defined as the stress which will increase the length of wire compared to its original length
(a) half
(b) same amount
(c) double
(d) one-fourth
(e) four times.Ans: b

15. Percentage reduction of area in performing tensile test on cast iron may be of the order of
(a) 50%
(b) 25%
(c) 0%
(d) 15%
(e) 60%.Ans: c

17. True stress-strain curve for materials is plotted between
(a) load/original cross-sectional area and change in length/original length
(b) load/instantaneous cross-sectional area original area and log.
(c) load/instantaneous cross-sectional area and change in length/original length
(d) load/instantaneous area and instantaneous area/original area
(e) none of the above.Ans: b

21. Which is the false statement about true stress-strain method
(a) It does not exist
(b) It is more sensitive to changes in both metallurgical and mechanical conditions
(c) It gives, a more accurate picture of the ductility
(d) It can be correlated with stress-strain values in other tests like torsion, impact, combined stress tests etc.
(e) It can be used for compression tests as well.Ans: a

22. In a tensile test on mild steel specimen, the breaking stress as compared to ultimate tensile stress is
(a) more
(b) less
(c) same
(d) more/less depending on composition
(e) may have any value.Ans: b

23. If a part is constrained to move and heated, it will develop
(a) principal stress
(b) tensile stress
(c) compressive stress
(d) shear stress
(e) no stress.Ans: c

24. Which of the following materials is most elastic
(a) rubber
(b) plastic
(c) brass
(d) steel
(e) glass.Ans: d

26. The value of Poisson’s ratio for steel is between
(a) 0.01 to 0.1
(b) 0.23 to 0.27
(c) 0.25 to 0.33
(d) 0.4 to 0.6
(e) 3 to 4.Ans: c

27. The buckling load for a given material depends on
(a) slenderness ratio and area of cross-section
(b) Poisson’s ratio and modulus of elasticity
(c) slenderness ratio and modulus of elasticity
(d) slenderness ratio, area of cross-section and modulus of elasticity
(e) Poisson’s ratio and slenderness ratio.Ans: d

28. The total elongation produced in a bar of uniform section hanging vertically downwards due to its own weight is equal to that produced by a weight
(a) of same magnitude as that of bar and applied at the lower end
(b) half the weight of bar applied at lower end
(c) half of the square of weight of bar applied at lower end
(d) one-fourth of weight of bar applied at lower end
(e) none of the above.Ans: b

29. The property of a material by virtue of which a body returns to its original, shape after removal of the load is called
(a) plasticity
(b) elasticity
(c) ductility
(d) malleability
(e) resilience.Ans: b

30. The materials which exhibit the same elastic properties in all directions are called
(a) homogeneous
(b) inelastic
(c) isotropic
(d) isentropic
(e) visco-elastic.Ans: c

35. The property of a material by virtue of which it can be beaten or rolled into plates is called
(a) malleability
(b) ductility
(c) plasticity
(d) elasticity
(e) reliability.
Ans: a

36. The change in the unit volume of a material under tension with increase in its Poisson’s ratio will ,
(a) increase
(b) decrease
(c) remain same
(d) increase initially and then decrease
(e) unpredictable.
Ans: b

37. The percentage reduction in area of a cast iron specimen during tensile test would be of the order of
(a) more than 50%
(b) 25—50%
(c) 10—25%
(d) 5—10%
(e) negligible.
Ans: e

40. The stress necessary to initiate yielding is
(a) considerably greater than that necessary to continue it
(b) considerably lesser than that necessary to continue it
(c) greater than that necessary to stop it
(d) lesser than that necessary to stop it
(e) equal to that necessary to stop it.
Ans: a

Strength of Materials Interview Questions and Answers pdf :-

41. In the tensile test, the phenomenon of slow extension of the material, i. e. stress increasing with the time at a constant load is called
(a) creeping
(b) yielding
(c) breaking
(d) plasticity
(e) none of the above.
Ans: a

42. The stress developed in a material at breaking point in extension is called
(a) breaking stress
(b) fracture stress
(c) yield point stress
(d) ultimate tensile stress
(e) proof stress.
Ans: a

47. The stress at which extension of the material takes place more quickly as compared to the increase in load is called
(a) elastic point of the material
(b) plastic point of the material
(c) breaking point of the material
(d) yielding point of the material
(e) ultimate point of the material.
Ans: d

48. In question 56, the internal reaction in bottom 80 cm length will be
(a) same in both cases
(b) zero in first case
(c) different in both cases
(d) data are not sufficient to determine same
(e) none of the above.
Ans: b

60. A beam is loaded as cantilever. If the load at the end is increased, the failure will occur
(a) in the middle
(b) at the tip below the load
(c) at the support
(d) anywhere
(e) none of the above.
Ans: d

61. A non-yielding support implies that the
(a) support is frictionless
(b) support can take any amount of reaction
(c) support holds member firmly
(d) slope of the beam at the support is zero
(e) none of the above.
Ans: d

62. The ratio of elongation in a prismatic bar due to its own weight (W) as compared to another similar bar carrying an additional weight (W) will be
(a) 1:2
(b) 1 : 3
(c) 1 : 4
(d) 1 : 2.5
(e) 1 : 2.25.
Ans: b

63. In a prismatic member made of two materials so joined that they deform equally under axial stress, the unit stresses in two materials are
(a) equal
(b) proportional to their respective moduli of elasticity
(c) inversely proportional to their moduli of elasticity
(d) average of the sum of moduli of elas-ticity
(e) none of the above.
Ans: b

64. In riveted boiler joints, all stresses, shearing, bearing and tensile are based on the
(a) size of rivet
(b) size of the drilled or reamed hole
(c) average of size of rivet and hole
(d) smaller of the two
(e) any one of the above.
Ans: b

65. The distance between the centres of the rivets in adjacent rows of zig-zag riveted joint is known as
(a) pitch
(b) back pitch
(c) diagonal pitch
(d) diametral pitch
(e) lap.
Ans: c

66. Efficiency of a riveted joint is the ratio of its strength (max. load it can resist without failure) to the strength of the unpunched plate in
(a) tension
(b) compression
(c) bearing
(d) any one of the above
(e) none of the above.
Ans: a

67. When two plates are butt together and riveted with cover plates with two rows of rivets, the joi;it is known as
(a) lap point
(b) butt joint
(c) single riveted single cover butt joint
(d) double riveted double cover butt joint
(e) single riveted double cover butt joint.
Ans: d

68. A riveted joint in which every rivet of a row is opposite to other rivet of the outer row, is known as
(a) chain riveted joint
(b) diamond riveted joint
(c) criss-cross riveted joint
(d) zig-zag riveted joint
(e) none of the above.
Ans: a

70. If the rivets in adjacent rows are staggered and the outermost row has only one rivet, the arrangement of the rivets is called
(a) chain riveting
(b) zig zag riveting
(c) diamond riveting
(d) criss-cross riveting
(e) none of the above.
Ans: c

71. Diamond riveted joint can be adopted in the case of following type of joint
(a) butt joint
(b) lap joint
(c) double riveted lap joints
(d) all types of joints
(e) none of the above.
Ans: a

73. The weakest section of a diamond riveting is the section which passes through
(a) the first row
(b) the second row
(c) the central row
(d) one rivet hole of the end row
(e) none of the above.
Ans: d

74. The deformation of a bar under its own weight compared to the deformation of same body subjected to a direct load equal to weight of the body is
(a) same
(b) double
(c) half
(d) four times
(e) one-fourth.
Ans: c

75. The force acting along the circumference will cause stress in the walls in a direction normal to the longitudinal axis of cylinder; this stress is called
(a) longitudinal stress
(b) hoop stress
(c) yeiled stress
(d) ultimate stress
(e) none of the above.
Ans: b

80. The torsional rigidity of a shaft is expressed by the
(a) maximum torque it can transmit
(b) number of cycles it undergoes before failure
(c) elastic limit up to which it resists torsion, shear and bending stresses
(d) torque required to produce a twist of one radian per unit length of shaft
(e) maximum power it can transmit at highest possible-speed.
Ans: d

81. The value of shear stress which is induced in the shaft due to the applied couple varies
(a) from maximum at the center to zero at the circumference
(b) from zero at the center to maximum at the circumference
(c) from maximum at the center to mini-mum at the cricumference
(d) from minimum at the centro to maxi-mum at the circumference
(e) none of the above.
Ans: b

82. A key is subjected to side pressure as well at shearing forces. These pressures are called
(a) bearing stresses
(b) fatigue stresses
(c) crushing stresses
(d) resultant stresses
(e) none of the above.
Ans: a

84. Shear stress induced in a shaft subjected to tension will be
(a) maximum at periphery and zero at center
(b) maximum at center
(c) uniform throughout
(d) average value in center
(e) none of the above.
Ans: e

85. If rain is falling in the opposite direction of the movement of a pedestrain, he has to hold his umbrella
(a) more inclined when moving
(b) less inclined when moving
(c) more inclined when standing
(d) less inclined when standing
(e) none of the above.
Ans: d

86. A projectile is fired at an angle 9 to the vertical. Its horizontal range will be maximum when 9 is
(a) 0°
(b) 30°
(c) 45°
(d) 60°
(e) 90°.
Ans: c

88. Limiting force of friction is the
(a) tangent of angle between normal-reaction and the resultant of normal reaction and limiting friction
(b) ratio of limiting friction and normal reaction
(c) the friction force acting when the body is just about to move
(d) the friction force acting when the body is in motion
(e) minimum force of friction.
Ans: c

93. Kinetic friction is the
(a) tangent of angle between normal reac-tion and the resultant of normal reac-tion and the limiting friction
(b) ratio of limiting friction and normal reaction
(c) the friction force acting when the body is just about to move
(d) the friction force acting when the body is in motion
(e) dynamic friction.
Ans: d

96. A semi-circular disc rests on a horizontal surface with its top flat surface horizontal and circular portion touching down. The coefficient of friction between semi-cricular disc and horizontal surface is i. This disc is to be pulled by a horizontal force applied at one edge and it always remains horizontal. When the disc is about to start moving, its top horizontal force will
(a) remain horizontal
(b) slant up towards direction of pull
(c) slant down towards direction of pull
(d) unpredictable
(e) none of the above.
Ans: c

98. The algebraic sum of moments of the forces forming couple about any point in their plane is
(a) equal to the moment of the couple
(b) constant
(c) both of above are correct
(d) both of above are wrong
(e) none of the above.
Ans: a

99. A single force and a couple acting in the
same plane upon a rigid body
(a) balance each other
(b) cannot balance each other
(c) produce moment of a couple
(d) are equivalent
(e) none of the above.
Ans: b

100. If three forces acting in one plane upon a rigid body, keep it in equilibrium, then they must either
(a) meet in a point
(b) be all parallel
(c) at least two of them must meet
(d) all the above are correct
(e) none of the above.
Ans: d

STRENGTH of Materials Objective Questions pdf ::

101. The maximum frictional force which comes into play when a body just begins to slide over another surface is called
(a) limiting friction
(b) sliding friction
(c) rolling friction
(d) kinematic friction
(e) dynamic friction.
Ans: a

102. The co-efficient of friction depends upon
(a) nature of surfaces
(b), area of contact
(c) shape of the surfaces
(d) ail of the above.
(e) (a) and (b) above.
Ans: a

104. The necessary condition for forces to be in equilibrium is that these should be
(a) coplanar
(b) meet at one point ;
(c) both (a) and (b) above
(d) all be equal
(e) something else.
Ans: c

105. If three forces acting in different planes can be represented by a triangle, these will be in
(a) non-equilibrium
(b) partial equilibrium
(c) full equilibrium
(d) unpredictable
(e) none of the above.
Ans: a

106. If n = number of members andy = number of joints, then for a perfect frame, n =
(a) j-2
(b)2j-l
(c) 2/-3
(d)3/-2
(e) 2/ -4.
Ans: c

108. A flywheel on a motor goes from rest to 1000 rpm in 6 sec. The number of revolutions made is nearly equal to
(a) 25
(b) 50
(c) 100
(d) 250
(e) 500.
Ans: b

109 Which of the following is the locus of a point that moves in such a manner that its distance from a fixed point is equal to its distance from a fixed line multiplied by a constant greater than one
(a) ellipse
(b) hyperbola
(c) parabola
(d) circle
(e) none of the above.
Ans: b

112. A sample of metal weighs 219 gms in air, 180 gms in water, 120 gms in an unknown fluid. Then which is correct statement about density of metal
(a) density of metal can’t be determined
(b) metal is twice as dense as water
(c) metal will float in water
(d) metal is twice as dense as unknown fluid
(e) none of the above.
Ans: a

113. The C.G. of a solid hemisphere lies on the central radius 3r
(a) at distance — from the plane base 3r
(b) at distance — from the plane base 3r
(c) at distance — from the plane base 3r
(d) at distance — from the plane base or
(e) at distance — from the plane base.
Ans: d

117. The C.G. of a plane lamina will not be at its geometrical centre in the case of a
(a) right angled triangle
(b) equilateral triangle
(c) square
(d) circle
(e) rectangle.
Ans: a

119. The C.G. of a right circular solid cone of height h lies at the following distance from the base
(a) h/2
(b) J/3
(c) h/6
(d) h/4
(e) 3/i/5.
Ans: d

122. The M.I. of hollow circular section about a central axis perpendicular to section as compared to its M.I. about horizontal axis is
(a) same
(b) double
(c) half
(d) four times
(e) one fourth.
Ans: b

126. Which of the following is the example of lever of first order
(a) arm of man
(b) pair of scissors
(c) pair of clinical tongs
(d) all of the above
(e) none of the above.
Ans: d

127. A pair of smith’s tongs is an example of the lever of
(a) zeioth order
(b) first order
(c) second order
(d) third order
(e) fourth order.
Ans: c

128. In the lever of third order, load W, effort P and fulcrum F are oriented as follows
(a) W between P and F
(b) F between W and P
(c) P between W and F
(d) W, P and F all on one side
(e) none of the above.
Ans: a

129. The angle which an inclined plane makes with the horizontal when a body placed on it is about to move down is known as angle of
(a) friction
(b) limiting friction
(c) repose
(d) kinematic friction
(e) static friction.
Ans: c